NEETChemistryChemical Equilibrium
Given below are two statements; one is labelled as Assertion (A) and the other is labelled as Reason(R). Assertion (A) : In the dissociation of ( PCl ₅ ) at constant pressure and temperature addition of helium at equilibrium increases the dissociation of ( PCl ₅ ). Reason (R) : Equilibrium constant changes only with change in temperature. In the light of the above statements, choose the most appropriate answer from t
Options
- ABoth (A) and (R) are correct but (R) is not the correct explanation of (A).
- B(A) is correct but (R) is not correct.
- C(A) is not correct but (R) is correct.
- DBoth (A) and (R) are correct and (R) is the correct explanation of (A).
Correct answer
A. Both (A) and (R) are correct but (R) is not the correct explanation of (A).
Step-by-step solution
- Assertion (A): In the dissociation of ( PCl ₅ ) at constant pressure and temperature, addition of helium at equilibrium increases the dissociation of ( PCl ₅ ). Correct. Reaction: ( PCl ₅(g) PCl ₃(g)+ Cl ₂(g) ) Number of moles increases ( (1 2 )). - If He is added at constant volume, no effect on equilibrium (only partial pressures change proportionally). - If He is added at constant pressure, the system volume increases. Partial pressures of reactants and products decrease, shifting equilibrium towards more gase